Barring my faulty memory (and if I’m not lazy) I want to post prayers on Monday from all over Church History and then throughout the modern day, and then my own. This one comes from the Catholic Church regarding Trinity Sunday.
To the one God, Father, Son, and Holy Spirit
that our lives may bear witness to our faith.
you sent your Word
to bring us truth
and your Spirit to make us holy.
Through them we come to know
the mystery of your life.
Help us to worship you,
one God in three Persons,
by proclaiming and living our faith in you.
We ask you this, Father, Son, and Holy Spirit,
one God, true and living, for ever and ever.